Insulated double walled drinking vessels and methods of making the same

ABSTRACT

An insulated drinking vessel, e.g., a wine glass, and a method of making the same is disclosed. The drinking vessel basically comprises an outer vessel, an inner vessel and a ring. The inner and outer vessels each include a sidewall. The sidewalls are spaced apart. At least one of the outer vessel, the inner vessel and the ring are pre-molded to form an integral structure having a vestige of a molding gate used to mold the integral structure. At least one of the inner and outer vessels and the ring is molded in situ on the integral structure to cause portions thereof to melt and intermingle to form a non-superficial homogenous joint, with the ring forming the rim or lip of the insulated drinking vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/837,570, filed on Aug. 27, 2015 entitled Insulated Double WalledDrinking Vessels and Methods of Making the Same, which in turn is acontinuation-in-part of U.S. application Ser. No. 14/696,907, filed onApr. 27, 2015 entitled Insulated Doubled Walled Drinking Vessel AndMethod Of Making The Same, now U.S. Pat. No. 9,451,842, which in turn isa continuation-in-part of U.S. application Ser. No. 14/694,363, filed onApr. 23, 2015 entitled Insulated Doubled Walled Drinking Vessel AndMethod Of Making The Same, which in turn claims priority from U.S.Provisional Application No. 61/987,147 filed on May 1, 2014 entitledInsulated Doubled Walled Drinking Vessel And Method Of Making The Same.The entire disclosures of all of the foregoing applications areincorporated by reference herein.

FIELD OF THE INVENTION

This invention relates generally to drinking vessels and moreparticularly to insulated drinking vessels having a thin rim and methodsof making the same.

BACKGROUND OF THE INVENTION

Double walled insulated drinking vessels are commercially available fromvarious vendors. There are also numerous U.S. Patents and publishedpatent applications directed to doubled walled insulated drinkingvessels, such as glasses, mugs, goblets, wine glasses and the like. Seefor example, U.S. Patents and published applications: U.S. Pat. No.4,872,569 (Bolte); U.S. Pat. No. 5,090,213 (Glassman); U.S. Pat No.5,553,735 (Kimura); U.S. Pat. No. 5,839,599 (Lin); U.S. Pat. No.6,050,443 (Tung et al.); U.S. Pat. No. 6,405,892 (Volan); U.S. Pat. No.6,419,108 (Toida et al.); U.S. Pat. No. 6,921,179 (Ghanem); U.S. Pat.No. 7,306,113 (El-Saden et al.); D519,785 (Bodum); D526,848 (Bodum);D557,561(Flowers et al.); 2004/0212120 (Giraud); 2005/0045643 (Ghanem);2005/0173365 (McKnight); and 2005/0194340 (Huang).

While the insulated drinking vessels of the foregoing prior art may begenerally suitable for their intended purposes, a need exists fordrinking vessel which has a thin, but relatively long, drinking lip. Thesubject invention addresses that need by providing insulated drinkingvessels and method of making those vessels. The drinking vessels areformed of an inner vessel component, and outer vessel component and aring component, one of which is molded in-situ on the other twocomponents which are preferably pre-molded components.

SUMMARY OF THE INVENTION

In accordance with one aspect of this invention an insulated drinkingvessel is provided. The insulated drinking vessel comprises a firstcomponent, a second component and a third component. The first componentis an inner vessel. The second component is an outer vessel. The thirdcomponent is a ring. Two of the first, second and third components arepre-molded of a plastic material. Two of the first, second, and thirdcomponents are fixedly secured together by a weld joint to form anintegral unit. One of the two components being pre-molded and having asurface which may include a vestige of a molding gate used to mold theone of the two components. Another of the first, second and thirdcomponents is molded in situ on the one of the components to causeportions thereof to melt and intermingle to form a non-superficialhomogenous joint therebetween. The outer vessel has a sidewall. Theinner vessel has a sidewall. The sidewall of the inner vessel is spacedfrom the sidewall of the outer vessel. The ring forms the lip of thedrinking vessel.

In accordance with one exemplary embodiment of the invention, the innervessel has a top edge portion, the outer vessel is a pre-molded plasticcomponent having a top edge portion, and the ring is a pre-moldedcomponent having a bottom edge portion which may include a vestige of amolding gate used to form the ring. The inner vessel is molded in-situon the bottom edge portion of the pre-molded ring cause the plasticmaterial thereof to fuse together and intermingle with the plasticmaterial of the ring to form a non-superficial homogenous jointeliminating the visible appearance of the vestige. The top edge portionof the outer vessel is fixedly secured to the bottom edge portion of thering at a weld joint.

In accordance with another exemplary embodiment of the invention, theinner vessel is a pre-molded component having a top portion and theouter vessel is a pre-molded component having a top portion. The innervessel and the outer vessel are joined together by a weld joint at thetop portions thereof to form a pre-molded unitary structure having a topedge portion which may include a vestige of a molding gate used to moldat least one of the inner and outer vessels. The ring comprises aplastic material molded in-situ on the top edge portion of thepre-molded unitary structure to cause the plastic material of the ringto fuse together and intermingle with the plastic material of thepre-molded unitary structure to form a non-superficial homogenous jointeliminating the visible appearance of the vestige.

In accordance with a preferred aspect of this invention the weld jointcomprises an annular projection located within an annular recess.

In accordance with a preferred aspect of this invention the ring is thinand relatively long, and may be optionally colored, while the inner andouter vessels are transparent. A decorative item may be located withinthe insulating air space.

Another aspect of this invention constitutes a method of making aninsulated double walled drinking vessel comprising an inner vessel, anouter vessel and a ring. The method basically entails providing an outervessel pre-molded of a plastic material and having a top edge portion. Aring pre-molded of a plastic material and having a bottom edge portionis also provided. The inner vessel is molded of a plastic materialin-situ on the bottom edge portion of the ring to cause the plasticmaterial thereof to fuse together and intermingle with the plasticmaterial of the ring to form a non-superficial homogenous joint at abottom edge portion of the ring.

If the ring includes any vestige of a gate used to mold the ring, thehomogeneous joint resulting from the in-situ molding of the inner vesselon the ring eliminates the visible appearance of that vestige. Thus,another aspect of the method of this invention entails pre-molding thering in a manner to ensure that any vestige of the molding gate used tomold the ring is located on the bottom edge portion of the ring.

Another aspect of this invention constitutes another method of making aninsulated double walled drinking vessel comprising an inner vessel, anouter vessel and a ring. The method basically entails providing an outervessel pre-molded of a plastic material and having a top portion andproviding an inner vessel of pre-molded of a plastic material and havinga top portion. The top edge portion of said inner vessel is fixedlysecured to the top edge portion outer vessel by a weld joint to form aunitary structure having a top edge portion which may include a vestigeof a molding gate used to mold at least one of the inner and outervessels. A ring of plastic material is molded in-situ on the top edgeportion of the pre-molded unitary structure to cause the plasticmaterial of the ring to fuse together and intermingle with the plasticmaterial of the pre-molded unitary structure to form a non-superficialhomogenous joint eliminating the visible appearance of the vestige. Thering forms the lip of said drinking vessel.

DESCRIPTION OF THE DRAWING

FIG. 1 is vertical sectional view of one exemplary insulated drinkingvessel, e.g., a wine glass, constructed in accordance with thisinvention;

FIG. 2 is an enlarged vertical sectional view of the ring componentmaking up the top portion of the wine glass shown in FIG. 1;

FIG. 3 is a more enlarged sectional view of the top portion of the wineglass shown during one step in the making thereof pursuant to a methodof this invention;

FIG. 4 is an enlarged sectional view, similar to FIG. 3, but showing thetop portion of the wine glass at a further step in the method of makingthe wine glass;

FIG. 5 is an enlarged sectional view of the portion of the wine glassshown within the circle designated as 5 in FIG. 1;

FIG. 6 is a block diagram of one exemplary method in accordance withthis invention for making an insulated vessel, such as the wine glassshown in FIG. 1;

FIG. 7 is a vertical sectional view similar to FIG. 1, but showinganother exemplary insulated drinking vessel, e.g., a wine glass,constructed in accordance with this invention;

FIG. 8 is an enlarged sectional view of the portion of the wine glassshown within the circle designated as 8 in FIG. 7;

FIG. 9 is an enlarged sectional view, similar to FIG. 8, but showing acorresponding portion of a third embodiment of a wine glass constructedin accordance with this invention; and

FIG. 10 is a block diagram of another exemplary method in accordancewith this invention for making an insulated vessel, such as the wineglasses shown in FIGS. 7 and 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the various figures of the drawing wherein likereference characters refer to like parts, there is shown at 20 in FIG. 1one exemplary embodiment of an insulated drinking vessel, e.g., astemmed wine glass, constructed in accordance with this invention. Thewine glass 20 basically comprises an outer vessel 22, an inner vessel24, and a ring 26. The outer vessel 22 is an integral unit that ispre-molded of any suitable transparent plastic material, e.g., EastmanTritan™ copolyester sold by Eastman Chemical Company. By pre-molded itis meant that the component is made prior to its use in the assembly ofthe insulated vessel 20. The ring 26 is also a pre-molded componentwhich forms the lip or rim of the wine glass 20 and includes a bottomsurface 26A (FIG. 2). Any suitable conventional molding technique, e.g.,blow molding, injection molding, etc., can be used to form the outervessel and the ring, although injection molding is preferred. Unlike theouter vessel and the ring, the inner vessel is not a pre-moldedcomponent. Rather, as will be described in detail later, it is moldedin-situ onto the bottom surface 26A of the ring 26 to form asubassembly, which is then welded to the outer vessel to complete theassembly of the wine glass 20,

As is known when a component is injection molded there will be somesurface portion thereof formed by the gate of the mold. This surfaceportion will typically exhibit a somewhat dissimilar appearance from thesurface of the component not at the location of the gate, therebydetracting from the aesthetics of the molded component. Thus, in theinterest of aesthetics, it is a common practice of the prior art totreat the surface area at the location of the gate to provide the sameappearance as the remainder of the molded component.

The subject invention entails a method of making the wine glass 20 whicheffectively eliminates any vestiges of a molding gate on the ring 26without requiring a separate surface treatment. To that end, it is ofimportance from an aesthetic standpoint that if the pre-molded ring hasany vestiges e.g., protrusions, etc., of the molding gate, such vestigesbe located on the bottom end surface 26A of the ring. In the exemplaryembodiment one such vestige 26B is shown.

As mentioned above the inner vessel is molded in-situ onto the ring inaccordance with a method of this invention. That method will bedescribed in detail later and is illustrated by the block diagram ofFIG. 6. Suffice it for now to state that the pre-molded ring 26 isplaced within an injection molding machine (not shown), with a portionof the bottom surface 26A of the ring 26 facing and contiguous with thetop of a mold cavity that is shaped like the inner vessel 24. A moltenplastic material, preferably the same material as that from which thering was pre-molded, is injected under pressure into the mold cavity tofill the mold cavity and thereby form the inner vessel 24. Moreover, andquite significantly, the molten injected plastic forming the innervessel 24 also engages the exposed bottom surface of the ring to causethat surface to melt and reflow to a substantial depth, e.g., within therange of approximately 0.003 inch −0.100 inch (preferably within therange of approximately 0.030 inch −0.080) inch, whereupon the injectedplastic intermingles with the melted plastic of the ring, to form anon-superficial homogenous joint thereat, thereby integrally joining thering 26 to the in-situ molded inner vessel 24. This non-superficialhomogeneous joint eliminates any vestige 26B of the molding gate,thereby resulting in joint having an aesthetically pleasing appearance,e.g., the joint appears invisible.

Thus, in accordance with a preferred aspect of the method of thisinvention the pre-molding of the ring 26 is accomplished so thatvestige(s) the gate of the mold in which the ring is made is(are)located at the bottom surface 26A of the ring. By pre-molding the ringso that the gate is located at the undersurface 26A of the ring, nosurface treatment of the vestige 26B needs to be undertaken with thesubject invention, since the molding of the inner vessel in-situ on theundersurface of the ring will completely eliminate or obscure theresidual appearance of the gate, i.e., the plastic material at thelocation of the gate will become molten and intermingle with the plasticmaterial forming the inner vessel, thereby eliminating any vestige ofthe gate.

The mold cavity for the in-situ molding of the inner vessel can be ofany suitable thickness and height to form the inner vessel. For example,the inside diameter of the mold cavity which forms the inner vessel 24is preferably chosen to be slightly larger than the inside diameter ofthe ring, whereupon during the in-situ molding operation when pressureis applied to the plastic forming the inner vessel, the inner surface ofthe inner vessel will be flush with the inner surface of the ring 26.

Once the inner vessel has been molded in-situ on the ring, the resultingsubassembly or unit of the ring and the inner vessel is allowed to coolto the point that it can be removed from the mold cavity and insertedinto the pre-molded outer vessel, so that the inner vessel of thesubassembly is located in the bowl portion (to be described later) ofthe outer vessel, with a top edge portion of the outer vessel abutting aportion of the bottom surface or edge of the ring. That assembly canthen be brought to a welding machine, e.g., an ultrasonic weldingmachine, to weld the ring with the inner vessel to the outer vessel.

The abutting surfaces of the ring and outer vessel at which anultrasonically welded joint is to be formed are preferably profiled orshaped in such a manner to concentrate the ultrasonic energy thereat tofacilitate the formation of a good weld joint. Thus, the abuttingsurfaces of the ring and outer vessel preferably make use of aconventional interference (e.g., double shear) joint. Alternatively,those surfaces may make use of a triangular protrusion energy director(e.g., an upstanding triangular annular protrusion from one flangesurface and an planar surface on the other flange) or any otherconventional joints or profiling that are known to those skilled in theart of ultrasonic welding, to create a good ultrasonic weld joint. Inthe exemplary embodiment shown and which will be described later, theabutting surfaces are in the form of a double shear, e.g., tongue andgroove, joint.

Once the assembly of the outer vessel and the ring with its attachedinner vessel is located in the ultrasonic welding machine, its horn orsonotrode can be applied to the top edge of the ring to produce a farfield weld at the interface of the ring and the outer vessel, therebycompleting the vessel 20. The resulting vessel exhibits the sameproperties as if it had been molded as an integral unit at one time,e.g., it exhibits the same resistance to breakage or other damage at thelocation of the joints between the ring and the inner and outer vesselsas remainder of the unit.

The details of the exemplary wine glass 20 will now be described. Thus,as best seen in FIG. 1, the outer vessel includes a bowl shaped portion28, a stem 30 and a flanged base 32. The bowl shaped portion 28 has asidewall 34 that is a surface of revolution and can be of any desiredshape. In the exemplary embodiment it is shown as being arcuate. Theinner vessel 24 is generally bowl shaped and includes an arcuatesidewall 36. The sidewall 36 is also a surface of revolution and can beof any desired shape. In the exemplary embodiment it is also arcuate. Asbest seen in FIGS. 2-4, the upper end of the sidewall 36 is in the formof an outwardly directed annular flange 40.

As mentioned above the abutting surfaces of the ring and outer vessel atwhich the ultrasonic joint is to be formed are preferably in the form ofa double shear, e.g., tongue and groove, interference joint. To thatend, as best seen in FIGS. 3 and 4, the top edge or upper surface 42 ofthe sidewall 34 of the outer vessel 22 includes an annular wall 44projecting upward therefrom. The annular wall 44 is chamfered at thepoint where it merges with the top surface 42 and forms the tongue ofthe tongue and groove joint. The height of the annular walls ispreferably within the range of 0.025 inch to 0.050 inch (and mostpreferably 0.04 inch). The thickness of the annular wall is preferablywithin the range of 0.025 inch to 0.05 inch (and most preferably 0.040inch). The annular wall or tongue 44 is arranged to be disposed within acorrespondingly shaped groove to form the tongue and groove interferencejoint. That groove is in the form of an annular recess 46 located in theportion 42 of the planar bottom surface 26A of the ring 26. The annularrecess 46 is correspondingly shaped to the annular wall 44 and includesa chamfered entryway contiguous with the undersurface portion 42.

While not preferable, the tongue and groove interference joint canalternatively be formed by having the annular groove 46 in the top edgeof the outer vessel 22 and the annular wall 44 project downward from theundersurface portion 42 of the ring 26. In fact, as mentioned above theabutting surfaces of the ring and the outer vessel may include otherfeatures or profiles to concentrate the ultrasonic welding energythereat in lieu of the exemplary tongue and groove joint.

The welding of the ring to the outer vessel is accomplished by placingthe horn or sonotrode of an ultrasonic welding device onto the topsurface 48 of the ring 26 to focus and direct the ultrasonic energy tothe engaging surfaces of the annular wall 44 and annular recess 46.Since the ring has a height of up to approximately 1 inch the weldproduced is constitutes what could be called a “far-field” weld. Duringthe welding operation, the annular wall 44 melts and flows into theannular recess 46 to form a strong welded joint therebetween, like shownin FIG. 5.

When the ring 26 with the inner vessel 24 is welded to the outer vesselas just described the outer surface of the sidewall 36 of the innervessel 24 is spaced from the inner surface of the sidewall 34 of theouter vessel 22 to form an insulating air space 50 therebetween. Ifdesired, an optional, decorative item, e.g., a wrap, an embroideredemblem or patch, etc., (not shown) can be disposed in the air spaceprior to the welding of the components to provide enhanced aestheticsfor the vessel 20. Irrespective of the construction of the decorativeitem, since it is disposed within the air space 50 and the sidewall ofthe outer vessel 22 is transparent, it will be visible through thetransparent sidewall to provide enhanced aesthetics to the insulatedvessel 20. Moreover, in the interest of aesthetics, the material formingthe ring 26 may be colored to accentuate the rim and to coordinate withthe ornamentation provided by the decorative item with in the insulatedair space. For example, the decorative item within the air space may bea wrap or embroidered patch bearing a college logo in the college'scolors, with the ring being colored to match one of the college's colorsfor emphasis.

If the insulated vessel is something other than a wine glass, e.g., is abottle, a helical thread may be provided on the outer surface of thering 26 to accommodate a threaded cap or lid for the insulated vessel.To that end, the mold cavity in which the ring is pre-molded may includehelical thread forming portion contiguous with the portion of the cavityforming the outer surface of the ring. Alternatively, the ring may beformed with an internal helical thread for a cap or lid. In such a case,the mold cavity may include helical thread forming portion contiguouswith the portion of the cavity forming the inner surface of the ring.Other features can be molded into the ring during its formation, e.g.,the top edge of the ring may include a portion of elevated height toform an enlarged lip for facilitating the drinking of a beverage fromthe vessel. A straw holder, not shown, may also be formed in the ring asthe ring is molded.

As mentioned above the method of making the insulated wine glass 20 (orany other double walled insulated drinking vessel constructed inaccordance with this invention) constitutes another aspect of thisinvention. To that end, as best seen in FIG. 6, the method entailsproviding a pre-molded ring formed of a plastic material. That ring isconstructed as discussed earlier. The ring is inserted into theinjection molding machine so that it is at the top of the injectionmolding machine's cavity for forming the inner vessel with its bottomsurface 26A contiguous with the portion of the mold cavity for formingthe inner vessel. The geometry of the molding machine cavity is suchthat a leak proof seal is created inside the cavity when the mold isclosed. This is accomplished by making the portion of the cavity thatthe ring is nested in of a smaller diameter by at least 0.004 inch thanthe inner diameter of the portion of the cavity forming the innersurface of the inner vessel. Moreover, it is desirable to have the moldcavity produce a land length of at least 0.060 inch.

The inner vessel is then molded in-situ on the bottom edge portion ofthe pre-molded ring, whereupon the heat and pressure applied causes theplastic material forming the inner vessel to fuse together andintermingle with the re-flow (melted) plastic material of the ring toform a non-superficial homogenous joint and with the inner vessel havingan inner surface that is flush with the inner surface of the ringvessel. Moreover, the gating of the inner vessel should be placed insuch a way as to give maximum heat to the re-flow area. Thus, it ispreferably located as close to the inner re-flow area as possible. Theparameters of the injection molding process are set in a way to createenough shear heat to re-flow the top surface of the inner vessel to formthe non-superficial homogeneous joint. For example, in accordance withone exemplary process of this invention, barrel heats are set to a rangebetween 530-560 degrees F. and pack and hold cavity pressures arebetween approximately 10,000 PSI to 12,000 PSI.

After the in-situ molding process is complete, the assembled unit orsubassembly of the ring and inner vessel is allowed to cool within theinjection molding machine until the molten plastic has solidifiedsufficiently that the subassembly can be removed to be welded to theouter vessel. To that end, the inner vessel 24 of the subassembly isplaced within the interior of the bowl shaped portion 28 of the outervessel, such that the annular wall 44 of the outer vessel is juxtaposedopposite the annular groove 46 in the undersurface 42 of the ring 26 asshown in FIG. 4. Those surfaces can then be brought into abutment witheach other with the sonotrode of the ultrasonic welding machine engagingthe top free edge or surface 48 of the ring 26 to apply pressure theretoand to focus and direct ultrasonic energy therefrom through the heightof the ring to the engaging surfaces of the annular wall 44 and annularrecess 46, to cause those surface to melt and fuse to form a good jointlike shown in FIG. 5. That action completes the vessel 20. Anothervessel can then be made in a similar manner as just described.

It should be pointed out at this juncture that the structure of theinsulated drinking vessel and method or making it as described above aremerely exemplary of various structures and methods that are contemplatedby this invention. Thus, for example, the insulated vessel 20 of thisinvention is not limited to wine glasses, but may be in the form ofmugs, tumblers, bottles, etc. Moreover, the sidewall portions of thevessels may be of other shapes and sizes than that shown in the drawing.Further still, while the wine glass 20 has been described as being madeby molding the inner vessel to the pre-molded ring and then assembling,e.g., welding, that subassembly to the outer vessel, it should be clearto those skilled in the art that the wine glass 20 (or any other doublewalled insulated drinking vessel) could be made by molding the outervessel in situ on the pre-molded ring to form a subassembly and theninserting and welding a pre-molded inner vessel into that subassembly tocomplete the formation of the wine glass/drinking vessel.

In FIG. 7 there is shown an alternative preferred embodiment 120 of awine glass constructed in accordance with this invention. The wine glass120 is similar in construction to the wine glass 20 except for thefeatures making up the region where the ring forming the rim of the wineglass joins the upper end portions of the inner and outer vessels. Thus,in the interest of brevity the components or features of the wine glass120 which are common to the wine glass 20 will be given the samereference numbers and the details of the construction of thosecomponents will not be reiterated.

The wine glass 120, or any other double walled drinking vesselconstructed in accordance with this invention, is preferably made inaccordance with the method that somewhat different than the methoddescribed above. That other method is shown schematically in the blockdiagram of FIG. 9 and basically entails providing a subassembly of apre-molded inner vessel disposed within a pre-molded outer vessel andmolding a ring of plastic in-situ onto the top end portion of thatsubassembly, whereas the exemplary embodiment 20 is made by moldingeither the inner or outer vessel onto the pre-molded ring.

Turning now to FIGS. 7 and 8 it can be seen that the wine glass 120 ismade up of an outer vessel 122, an inner vessel 124 and an annular ring126. The outer vessel 122 includes a bowl shaped portion 28, a stem 30and a flanged base 32. The bowl shaped portion 28 has a sidewall 34 thatis a surface of revolution and can be of any desired shape. In theexemplary embodiment it is shown as being arcuate. The inner vessel 124is generally bowl shaped and includes an arcuate sidewall 36. Thesidewall 36 is also a surface of revolution and can be of any desiredshape. In the exemplary embodiment it is also arcuate. The upper end ofthe sidewall 36 of the inner vessel is in the form of an outwardlydirected annular flange 140 having a top surface 138. The upper endsurface 142 of the sidewall 34 of the outer vessel 122 at the pointwhere it meets the inner surface of the sidewall 34 is in the form of anannular recess or ledge 146. The recess 146 is configured to receive theannual flange 140 so that the outer surface of the sidewall 36 of theinner vessel will be spaced from the inner surface of the sidewall 34 ofthe outer vessel to form an insulating air space 50 therebetween. Ifdesired, an optional, decorative item, e.g., a wrap, an embroideredemblem or patch, etc., like that described earlier can be disposed inthat air space.

Turning now to FIG. 9, there is shown the details of a portion of analternative embodiment of the wine glass 220. The wine glass 220 isconstructed similarly to the wine glass 120 of FIG. 7, except for thedetails of the top end portions of its inner vessel and its outervessel. In the interest of brevity the components or features of thewine glass 220 which are common to the wine glasses 20 and 120 will begiven the same reference numbers and the details of the construction ofthose components will not be reiterated. Thus, it can be seen that thewine glass 220 includes an outer vessel 22, an inner vessel 224 and anannular ring 126. The outer vessel 22 of the wine glass 220 is identicalin construction to the outer vessel 22 of the wine glass 20. Thus, upperend of the sidewall 36 of the outer vessel 22 includes an annular wall44 projecting upward therefrom. The annular wall 44 is chamfered at thepoint where it merges with the top surface 42 of the outer sidewall toform the tongue of the tongue and groove double shear interference jointwith the inner vessel. The top portion of the inner vessel 224 includesan outwardly projecting annular flange 240 having an undercut surface inwhich an annular recess 246 is located. The annular recess 246 isidentical in construction to the annular recess 46 of the wine glass 20and is correspondingly shaped to the annular wall 44 of the outer vessel22. Thus the annular recess 246 includes a chamfered entryway contiguouswith the undersurface of the flange 240.

The method of making the wine glass 120 is as follows and is shown inthe block diagram of FIG. 10. To that end, a pre-molded plastic innervessel 124 constructed as described above and a pre-molded outer vessel122 also constructed as described above are assembled together to form asubassembly with the inner vessel disposed within the interior of thebowl shaped portion 28 of the outer vessel 122 and with the annularflange 140 of the inner vessel 124 disposed within and in engagementwith the annular recess 146 in the top edge 142 of the outer vessel 122.Preferably the inner vessel is secured to the outer vessel, such as by aweld joint at their abutting surfaces. However, it should be clear thatthe inner vessel and outer vessel need not be permanent secured togetherto form the subassembly since they will be permanently secured togetherwhen the ring 126 is molded in-situ on that subassembly, as will bedescribed shortly. Thus, the inner vessel may merely be seated withinthe outer vessel or can be snap fit within the outer vessel.

If the subassembly is to be welded to permanently join the inner andouter vessels together before forming the ring on that subassembly, thewelding operation can be readily accomplished by applying the sonotrodeof the ultrasonic welding machine to the top surface 138 of the innervessel 124 adjacent the location where the annular flange 140 isreceived in the annular recess 146 to apply pressure thereto and tofocus and direct ultrasonic energy to the engaging surfaces. That actioncauses those surfaces to melt and fuse to form a good joint like shownin Fig.8, thereby joining the inner and outer vessels together into apermanent subassembly. The subassembly can then be inserted into aninjection molding machine (not shown) so the top end, i.e., thecontiguous surfaces 138 and 142 of the subassembly is locatedimmediately below a ring-shaped annular cavity of the injection moldingmachine for forming the ring 126. The geometry of the molding machinecavity is such that a leak proof seal is created inside the cavity whenthe mold is closed. This is accomplished by making the portion of thecavity that the subassembly is nested in of a smaller diameter by atleast 0.003 inch than the inner diameter of the portion of the cavityforming the inner surface of the ring. Moreover, it is desirable to havethe mold cavity produce a land length of at least 0.080 inch.

The ring 126 is then molded in-situ on the top surface portion 138 and142 of the subassembly, whereupon the heat and pressure applied causesthe plastic material forming the ring to fuse together and interminglewith the re-flow (melted) plastic material of the subassembly to form anon-superficial homogenous joint and with the ring having an innersurface that is flush with the inner surface of the subassembly.Moreover, the gating of the ring should be placed in such a way as togive maximum heat to the re-flow area. Thus, it is preferably located asclose to the inner re-flow area as possible. The parameters of theinjection molding process are set in a way to create enough shear heatto re-flow the top surface of the subassembly to form thenon-superficial homogeneous joint. For example, in accordance with oneexemplary process of this invention, barrel heats are set to a rangebetween 400-440 degrees F. and pack and hold cavity pressures arebetween approximately 800 PSI to 1200 PSI. The non-superficialhomogeneous joint produced by molding the ring onto the subassembly willalso have the effect of eliminating any vestige of the molding gate thatwas used to mold the inner and outer vessel, if the vestige of themolding gate was located on the top surface 138 of the inner vessel oron the top surface 142 of the outer vessel. Thus, the joint createdbetween the ring 126 and the subassembly of the inner vessel and outervessel will have an aesthetically pleasing appearance, e.g., the jointappears invisible.

If desired to enhance the structural integrity of the joint createdbetween the ring 126 and the subassembly of the inner and outer vesselsthe top surface 138 and/or the top surface 142 may include an upstandingannular wall (like the wall 44) or may include an annular recess (likethe recess 46) to provide more surface area for the ring 126 to engageand intermingle with when the ring is molded in-situ onto thesubassembly.

In any case, as should be appreciated by those skilled in the art, themolding of the ring 126 onto the subassembly of the inner and outervessels has the effect of permanently joining those vessels together,even if the subassembly of those two vessels had not been previouslypermanently secured together, e.g., welded. In particular, if the innervessel had merely been located within the outer vessel to form atemporarily connected subassembly, the molding of the ring 126 in-situon that subassembly will fixedly secure the vessels together. Thus,after the in-situ molding process is complete, the assembled unit isallowed to cool within the injection molding machine until the moltenplastic has solidified sufficiently such that the unit can be removed.That action completes the vessel 120. Another vessel can then be made ina similar manner as just described.

It should be pointed out at this juncture, that the method of making thewine glass 220, or any other double walled drinking vessel, be it atumbler, mug, etc., can be achieved in accordance with the methoddescribed above with respect to FIG. 10. In particular, a pre-moldedplastic inner vessel 224 constructed as described above and a pre-moldedouter vessel 22 also constructed as described above are assembledtogether to form a subassembly with the inner vessel disposed within theinterior of the bowl shaped portion of the outer vessel and with theannular wall 44 of the outer vessel 22 disposed within and in engagementwith the annular recess 246 in the undersurface of the flange 240 of theinner vessel 224. Those two engaging portions can then be weldedtogether by applying the sonotrode of the ultrasonic welding machine tothe top surface of the flange 240 to apply pressure thereto and to focusand direct ultrasonic energy to the engaging surfaces. That actioncauses those surfaces to melt and fuse to form a good joint like shownin Fig.9, thereby joining the inner and outer vessels together into apermanent subassembly. The subassembly can then be inserted into aninjection molding machine and the ring 126 molded in-situ thereon in thesame manner as described above with reference to the formation of thewine glass 120.

Without further elaboration the foregoing will so fully illustrate ourinvention that others may, by applying current or future knowledge,adopt the same for use under various conditions of service.

We claim:
 1. A double walled vessel comprising: a) an outer vesselcomprising a separate pre-molded component formed of a plastic material;b) an inner vessel; and c) a ring, wherein either one of said innervessel and said ring also comprises a separate pre-molded componentformed of a plastic material and being referred to as a second separatepre-molded component, and wherein the remaining one of said inner vesseland said ring which is not a separate pre-molded component beingreferred to as a final stage component, said outer vessel and saidsecond separate pre-molded component being fixedly secured together by aweld joint to form an integral unit, said final stage component beingmolded in situ on either of said outer vessel or said second separatepre-molded component to cause portions thereof to melt and intermingleto form a non-superficial homogenous joint therebetween, said ringforming a lip of said double walled vessel.
 2. The double walled vesselof claim 1 wherein said outer vessel has a top edge portion, said ringcomprises said second separate pre-molded component having a bottom edgeportion which may include a vestige of a molding gate used to form saidring, and wherein said inner vessel comprises said final stage componentthat is molded in-situ on said bottom edge portion of said pre-moldedring which causes the plastic material thereof to fuse together andintermingle with said plastic material of said ring to form anon-superficial homogenous joint eliminating the visible appearance ofsaid vestige, said top edge portion of said outer vessel being fixedlysecured to said bottom edge portion of said ring at a weld joint.
 3. Thedouble walled vessel of claim 2 wherein said weld joint comprises anannular projection located within an annular recess.
 4. The doublewalled vessel of claim 2 wherein said weld joint comprises a far-fieldultrasonically welded joint.
 5. The double walled vessel of claim 2wherein said double walled vessel is an insulated drinking vessel. 6.The double walled vessel of claim 1 wherein said inner vessel is apre-molded component having a top portion, said outer vessel is apre-molded component having a top portion, said inner vessel and saidouter vessel being joined together by a weld joint at said top portionsthereof to form a pre-molded unitary structure having a top edge portionwhich may include a vestige of a molding gate used to mold at least oneof said inner and outer vessels, said ring comprising a plastic materialmolded in-situ on said top edge portion of said pre-molded unitarystructure to cause said plastic material of said ring to fuse togetherand intermingle with said plastic material of said pre-molded unitarystructure to form a non-superficial homogenous joint eliminating thevisible appearance of said vestige.
 7. The double walled vessel of claim6 wherein said weld joint comprises an annular projection located withinan annular recess.
 8. The double walled vessel of claim 6 wherein saidweld joint comprises a far-field ultrasonically welded joint.
 9. Thedouble walled vessel of claim 6 wherein said double walled vessel is aninsulated drinking vessel.
 10. A method for making a double walledvessel comprising: a) providing an outer vessel comprising a separatepre-molded component formed of a plastic material; b) providing an innervessel; c) providing a ring, wherein either one of said inner vessel andsaid ring comprises a separate pre-molded component formed of a plasticmaterial and being referred to as a second separate pre-moldedcomponent, and wherein the remaining one of said inner vessel and saidring which is not a separate pre-molded component being referred to as afinal stage component; and d) fixedly securing said outer vessel andsaid second separate pre-molded component together by a weld joint toform an integral unit, said final stage component being molded in situon either of said outer vessel or said second separate pre-moldedcomponent to cause portions thereof to melt and intermingle to form anon-superficial homogenous joint therebetween, said ring forming a lipof said double walled vessel.
 11. The method of claim 10 wherein saidouter vessel has a top edge portion, wherein said ring is pre-molded ofa plastic material and has a bottom edge portion, and wherein saidmethod comprises molding said inner vessel in-situ on said bottom edgeportion of said ring to cause the plastic material thereof to fusetogether and intermingle with said plastic material of said ring to forma non-superficial homogenous joint at a bottom edge portion of saidring, and fixedly securing said top edge portion of said outer vessel toa bottom edge portion of said ring by a weld joint.
 12. The method ofclaim 11 wherein said bottom edge portion of said ring includes avestige of a molding gate used to form said ring and wherein theformation of said homogenous joint eliminates the visible appearance ofsaid vestige.
 13. The method of claim 11 wherein said weld jointcomprises an annular projection located within an annular recess. 14.The method of claim 11 wherein said weld joint comprises a far-fieldultrasonically welded joint.
 15. The method of claim 11 wherein saiddouble walled vessel is an insulated vessel, wherein said inner vesselcomprises a sidewall and said outer vessel comprises a sidewall and saidsidewall of said inner vessel is separated from said sidewall of saidouter vessel by an insulating space.
 16. The method of claim 10 whereinsaid outer vessel has a top edge portion, wherein said inner vessel ispre-molded of pre-molded of a plastic material and has a top portion,and wherein said method comprises fixedly securing said top edge portionof said inner vessel to said top edge portion outer vessel by a weldjoint to form a unitary structure having a top edge portion which mayinclude a vestige of a molding gate used to mold at least one of theinner and outer vessels, and molding said ring in-situ on said top edgeportion of said pre-molded unitary structure to cause the plasticmaterial of said ring to fuse together and intermingle with said plasticmaterial of said pre-molded unitary structure to form a non-superficialhomogenous joint.
 17. The method of claim 16 wherein said bottom edgeportion of said ring includes a vestige of a molding gate used to formsaid ring and wherein the formation of said homogenous joint eliminatesthe visible appearance of said vestige.
 18. The method of claim 16wherein said weld joint comprises an annular projection located withinan annular recess.
 19. The method of claim 16 wherein said weld jointcomprises a far-field ultrasonically welded joint.
 20. The method ofclaim 14 wherein said double walled vessel is an insulated vessel,wherein said inner vessel comprises a sidewall and said outer vesselcomprises a sidewall and said sidewall of said inner vessel is separatedfrom said sidewall of said outer vessel by an insulating space.